One is to use the Mash Calculator that you can find under the WIndow menu. That will allow you to enter a lot of the parameters of your mash and calculate estimated mash and sparge temperatures.

Another, ultimately more efficient, method is to set up a mash schedules under the Schedule Display. That will allow you to set up a typical mash procedure, calibrated to your equipment, which will automatically calculate the volumes and temperatures for each specific recipe.